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The sum of first n odd natural numbers is equal to …………….

The sum of first 30 natural numbers is:

Find the sum of first n natural numbers.

Find the sum of first 100 natural numbers.

The arithmetic mean of first n odd natural numbers is :

The sum of the first n odd number is :

If the sum of first n even natural numbers is equal to k times the sum of first n odd natural numbers, then k is equal to:

Sum of first 10 odd numbers is ________

Sum of two natural numbers is a rational number.